54 resultados para fill

em Université de Lausanne, Switzerland


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The depositional stratigraphy of within-channel deposits in sandy braided rivers is dominated by a variety of barforms (both singular `unit' bars and complex `compound' bars), as well as the infill of individual channels (herein termed `channel fills'). The deposits of bars and channel fills define the key components of facies models for braided rivers and their within-channel heterogeneity, knowledge of which is important for reservoir characterization. However, few studies have sought to address the question of whether the deposits of bars and channel fills can be readily differentiated from each other. This paper presents the first quantitative study to achieve this aim, using aerial images of an evolving modern sandy braided river and geophysical imaging of its subsurface deposits. Aerial photographs taken between 2000 and 2004 document the abandonment and fill of a 1 3 km long, 80 m wide anabranch channel in the sandy braided South Saskatchewan River, Canada. Upstream river regulation traps the majority of very fine sediment and there is little clay (<1%) in the bed sediments. Channel abandonment was initiated by a series of unit bars that stalled and progressively blocked the anabranch entrance, together with dune deposition and stacking at the anabranch entrance and exit. Complete channel abandonment and subsequent fill of up to 3 m of sediment took approximately two years. Thirteen kilometres of ground-penetrating radar surveys, coupled with 18 cores, were obtained over the channel fill and an adjacent 750 m long, 400 m wide, compound bar, enabling a quantitative analysis of the channel and bar deposits. Results show that, in terms of grain-size trends, facies proportions and scale of deposits, there are only subtle differences between the channel fill and bar deposits which, therefore, renders them indistinguishable. Thus, it may be inappropriate to assign different geometric and sedimentological attributes to channel fill and bar facies in object-based models of sandy braided river alluvial architecture.

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The objective of this work was to develop an easily applicable technique and a standardized protocol for high-quality post-mortem angiography. This protocol should (1) increase the radiological interpretation by decreasing artifacts due to the perfusion and by reaching a complete filling of the vascular system and (2) ease and standardize the execution of the examination. To this aim, 45 human corpses were investigated by post-mortem computed tomography (CT) angiography using different perfusion protocols, a modified heart-lung machine and a new contrast agent mixture, specifically developed for post-mortem investigations. The quality of the CT angiographies was evaluated radiologically by observing the filling of the vascular system and assessing the interpretability of the resulting images and by comparing radiological diagnoses to conventional autopsy conclusions. Post-mortem angiography yielded satisfactory results provided that the volumes of the injected contrast agent mixture were high enough to completely fill the vascular system. In order to avoid artifacts due to the post-mortem perfusion, a minimum of three angiographic phases and one native scan had to be performed. These findings were taken into account to develop a protocol for quality post-mortem CT angiography that minimizes the risk of radiological misinterpretation. The proposed protocol is easy applicable in a standardized way and yields high-quality radiologically interpretable visualization of the vascular system in post-mortem investigations.

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The 24-km diameter Ries crater, Germany, exhibits well-preserved crater filling and surficial melt-rich breccia deposits that are believed to have been altered by post-impact hydrothermal fluids. The alteration mineralogy of the crater filling breccias is characterized by clay (smectite, chlorite) and a zeolite assemblage, and secondary clay phases (smectite, minor halloysite) in surficial melt-bearing breccia deposits. Using stable isotope analysis of secondary smectitic clay fractions, evidence of significant hydrous alteration of impactites at large water/rock ratios was found. The estimated fluid temperatures, using data derived by delta(18)O and delta D fractionation, suggest smectite precipitation in surficial breccias in equilibrium with meteoric fluids at temperatures 16 +/- 5 degrees C in agreement with the long-term variation of modern precipitation in the area. The stable isotope composition of smectite in crater-fill breccia, however, suggests a trend of monotonously increasing temperatures from 43 to 112 degrees C. with increasing depth through the breccia sequence. This demonstrates a different origin of alteration and temperature distribution for the surficial and crater filling melt-bearing impact breccias in the Ries crater. Our results suggest that the inverted structure of hydrothermal systems observed in some terrestrial impact craters, including the Ries crater, could indicate the initial configuration of a thermal anomaly in the crater filling sequence, but which is replaced with a normal hydrothermal convection in crater proper, during the course of post-impact cooling. (C) 2010 Elsevier B.V. All rights reserved.

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A high-resolution three-dimensional (3-D) seismic reflection survey was conducted in Lake Geneva, near the city of Lausanne, Switzerland, as part of a project for developing such seismic techniques. Using a single 48-channel streamer, the 3-D site with an area of 1200 m x 600 m was surveyed in 10 days. A variety of complex geologic structures (e.g. thrusts, folds, channel-fill) up to similar to150 m below the water bottom were obtained with a 15 in.(3) water gun. The 3-D data allowed the construction of an accurate velocity model and the distinction of five major seismic facies within the Lower Freshwater Molasse (Aquitanian) and the Quaternary sedimentary units. Additionally, the Plateau Molasse (PM) and Subalpine Molasse (SM) erosional surface, "La Paudeze" thrust fault (PM-SM boundary) and the thickness of Quaternary sediments were accurately delineated in 3-D.

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SUMMARYThe innate immune system plays a central role in host defenses against invading pathogens. Innate immune cells sense the presence of pathogens through pattern recognition receptors that trigger intracellular signaling, leading to the production of pro-inflammatory mediators like cytokines, which shape innate and adaptive immune responses. Both by excess and by default inflammation may be detrimental to the host. Indeed, severe sepsis and septic shock are lethal complications of infections characterized by a dysregulated inflammatory response.In recent years, members of the superfamily of histone deacetylases have been the focus of great interest. In mammals, histone deacetylases are broadly classified into two main subfamilies comprising histone deacetylases 1-11 (HDAC1-11) and sirtuins 1-7 (SIRT1-7). These enzymes influence gene expression by deacetylating histones and numerous non-histone proteins. Histone deacetylases have been involved in the development of oncologic, metabolic, cardiovascular, neurodegenerative and autoimmune diseases. Pharmacological modulators of histone deacetylase activity, principally inhibitors, have been developed for the treatment of cancer and metabolic diseases. When we initiated this project, several studies suggested that inhibitors of HDAC 1-11 have anti-inflammatory activity. Yet, their influence on innate immune responses was largely uncharacterized. The present study was initiated to fill in this gap.In the first part of this work, we report the first comprehensive study of the effects of HDAC 1- 11 inhibitors on innate immune responses in vitro and in vivo. Strikingly, expression studies revealed that HDAC1-11 inhibitors act essentially as negative regulators of basal and microbial product- induced expression of critical immune receptors and antimicrobial products by mouse and human innate immune cells like macrophages and dendritic cells. Furthermore, we describe a new molecular mechanism whereby HDAC1-11 inhibitors repress pro-inflammatory cytokine expression through the induction of the expression and the activity of the transcriptional repressor Μί-2β. HDAC1-11 inhibitors also impair the potential of macrophages to engulf and kill bacteria. Finally, mice treated with an HDAC inhibitor are more susceptible to non-severe bacterial and fungal infection, but are protected against toxic and septic shock. Altogether these data support the concept that HDAC 1-11 inhibitors have potent anti-inflammatory and immunomodulatory activities in vitro and in vivo.Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that plays a central role in innate immune responses, cell proliferation and oncogenesis. In the second part of this manuscript, we demonstrate that HDAC1-11 inhibitors inhibit MIF expression in vitro and in vivo and describe a novel molecular mechanism accounting for these effects. We propose that inhibition of MIF expression by HDAC 1-11 inhibitors may contribute to the antitumorigenic and anti-inflammatory effects of these drugs.NAD+ is an essential cofactor of sirtuins activity and one of the major sources of energy within the cells. Therefore, sirtuins link deacetylation to NAD+ metabolism and energy status. In the last part of this thesis, we report preliminary results indicating that a pharmacological inhibitor of SIRT1-2 drastically decreases pro-inflammatory cytokine production (RNA and protein) and interferes with MAP kinase intracellular signal transduction pathway in macrophages. Moreover, administration of the SIRT1-2 inhibitor protects mice from lethal endotoxic shock and septic shock.Overall, our studies demonstrate that inhibitors of HDAC1-11 and sirtuins are powerful anti-inflammatory molecules. Given their profound negative impact on the host antimicrobial defence response, these inhibitors might increase the susceptibility to opportunistic infections, especially in immunocompromised cancer patients. Yet, these inhibitors might be useful to control the inflammatory response in severely ill septic patients or in patients suffering from chronic inflammatory diseases.

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Hip fractures place a major and increasing burden on health services in Western countries. Reported incidence rates vary considerably from one geographic area to another. No published data are available for Switzerland or surrounding countries, but such descriptive indicators are indispensable in orienting national or regional policies. To fill this gap and to assess the similarity of hip fracture incidence in Switzerland and other countries, we collected data from several sources in 26 public and private hospitals, in the Canton of Vaud (total population: 538,000) for 1986, which allowed us to calculate the incidence (for people over twenty years old) and assess related parameters. 577 hip fractures were identified among the resident population, indicating a crude average annual incidence rate of 140 per 100,000 (95% confidence interval: 128, 152). Corresponding rates for males and females were 58 (47, 68) and 213 (193, 232). Standardized rates and international comparisons show that Swiss rates are slightly lower than those of most industrial countries. More detailed results of relative risks for various study variables are presented and the pathogenesis of hip fractures is discussed.

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The history of the opening seaway from the westernmost Tethys to the Central Atlantic is traced by the analysis of the sedimentary facies development in the external Rif basin of Northern Morocco and the geological and seismic data from the Moroccan Atlantic continental margin. In the Rif basin, after the early Sinemurian, sedimentary facies dated by ammonites, foraminifers and brachiopods, indicate a progression of rapid subsidence resulting from extensional tectonic (tilted blocks, escarpment fault breccias, neptunian dykes etc.) from the N and NE to the S and SW. From the Toarcian to the Bajocian, deltas progress from the W and SW into the `'Rides sud-rifaines'' realm. From the late Bathonian to the Oxfordian, deep-sea fans develop in the external Rif. During the same period, deltaic sediments fill in the Middle Atlas basin of Eastern Morocco and progress into the external Rif. The top of the Jurassic is characterised by carbonate deposits. At the northwestern corner of Africa, the subsidence of the sedimentary basins by rifting is initiated in the late Triassic; however, at the Mazagan transect of the Atlantic continental margin, the tectonic pattern characteristic of a passive continental margin appears clearly only in the early Jurassic. At the foot of the Mazagan escarpment, the sedimentary record shows a foundering of the first bloc during early to middle Lias. A thermal uplift phase is indicated by emersion of the African margin shoulder in late Liassic, and thermal relaxation starts in the middle Jurassic. The morphology of this transect, compared with the conjugate side of the American continent is most easily explained by the uniform sense simple shear model.

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La thématique des désaffiliations religieuses du milieu évangélique est le parent pauvre des études faites jusqu'à ce jour sur ce courant religieux. En effet, l'accent est généralement mis sur son développement en termes d'affiliation faisant alors l'impasse sur les pertes qu'il connaît pourtant. De plus, la question des désaffiliations religieuses est un angle d'approche sociologique particulièrement fécond pour étudier les groupes religieux en permettant, entre autres, de cerner plus en profondeur leur identité, les mécanismes qui favorisent leur pérennisation, mais aussi leur rapport à la société environnante. Dans ce travail, qui s'inscrit en sociologie des religions et qui puise autant dans la littérature sur les désaffiliations religieuses que dans celle des désengagements militants, l'analyse s'est focalisée sur les processus de désengagement au niveau microsociologique : quels sont les motifs qui président les désaffiliations, comment se déroulent ces dernières, quels effets ont-elles sur l'individu en termes identitaires et comment sont-elles perçues par ceux qui restent ? Ces principales questions ont permis de (re] questionner des éléments constitutifs de l'engagement évangélique : les processus de socialisation ; la structuration des liens intragroupe développés par le milieu et son rapport à l'extérieur ; son système normatif; son système de représentation du monde et la démarche religieuse qu'il valorise, qui sont autant d'aspects qui jouent un rôle dans les processus de désaffiliation. Plus précisément, ces éléments agissent en tant que mécanismes de rétention tant sociaux que psychologiques compliquant ainsi le désengagement. Cette thèse s'est construite sur dix-sept entretiens semi directifs menés auprès de personnes ayant grandi pour la plupart dans une famille évangélique et qui ont décidé, un jour, de ne plus fréquenter ce milieu religieux. Pour élargir la perspective analytique et pour permettre de comprendre et d'expliquer les processus de désaffiliation en lien avec le groupe quitté, un ensemble de septante-huit entretiens semi directifs et de mille cent questionnaires standardisés de membres d'Eglises évangéliques a été mobilisé. Partant des logiques du désengagement, cette thèse affine les connaissances actuelles sur l'évangélisme dans le contexte de la modernité, grâce à l'éclairage inédit qu'elle lui donne. Elle développe également le champ des connaissances sur les désaffiliations religieuses en lui fournissant un nouvel exemple de cas tout en lui offrant une autre façon de théoriser les sorties de groupes religieux qui valorisent un engagement de type militant. - Religious disaffiliations from the evangelical milieu have not yet been investigated. Indeed, former studies have usually focused on the development of the milieu by looking at conversions. However, it appears that the study of the disaffiliation processes may not only give results on the reasons and experiences of those disaffiliating, but also shed light on the attributes and the development of the evangelical milieu itself. The main goal of this thesis was to fill this gap in the literature. From a microsociological approach, this thesis sought to answer the following central question : Why, how and with what effects do individuals leave the evangelical milieu and how is this phenomenon perceived, interpreted and managed by the individuals who leave the evangelical community and by the members of the evangelical milieu? These questions enabled me to investigate the functioning of the evangelical milieu : its processes of socialization ; internal and external relationships ; normative system ; belief system or its religious engagement. This set of aspects can influence and complicate the processes of disaffiliation. The analysis of religious disaffiliation was based on seventeen qualitative interviews with former members of evangelical chrurches who decided, one day, not to attend an evangelical church anymore and who question more or less strongly the « system of evangelical thought ». Seventy-eight qualitative interviews with members of evangelical free churches and a representative survey with members of evangelical free churches (N = 1100] completed the analysis and inserted the individual disengagement in the « milieu's logics ». This thesis complements and enriches the literature on evangelism as well as on religious disaffiliation in general.

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The present study aims to identify organisational antecedents of public service motivation (PSM). Numerous research has been devoted to the identification of socio-demographic PSM antecedents, or to its outcomes. However, organisational antecedents are understudied thus far. In order to fill this research gap, we question whether human resources management practices, whether intrinsic or extrinsic ones, might be related to PSM. Drawing on person-environment fit theoretical assumptions, we depart from the idea that PSM may be developed or sustained by HRM practices, which might contribute to create an environment allowing public employees to fulfill their needs or personal aspirations. Based upon a survey in an important Swiss municipality (N = 859), our findings surprisingly highlight that extrinsic HRM practices are significantly related to PSM, whereas intrinsic ones are not. Furthermore, when taking into account work-related outcomes, such as job satisfaction and organisational commitment, there is evidence of full mediation effects towards extrinsic HRM practices from organisational commitment. Astonishingly, neither job satisfaction nor intrinsic HRM practices are significantly related to PSM.

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An efficient high-resolution (HR) three-dimensional (3D) seismic reflection system for small-scale targets in lacustrine settings was developed. In Lake Geneva, near the city of Lausanne, Switzerland, the offshore extension of a complex fault zone well mapped on land was chosen for testing our system. A preliminary two-dimensional seismic survey indicated structures that include a thin (<40 m) layer of subhorizontal Quaternary sediments that unconformably overlie south-east-dipping Tertiary Molasse beds and a major fault zone (Paudeze Fault Zone) that separates Plateau and Subalpine Molasse (SM) units. A 3D survey was conducted over this test site using a newly developed three-streamer system. It provided high-quality data with a penetration to depths of 300 m below the water bottom of non-aliased signal for dips up to 30degrees and with a maximum vertical resolution of 1.1 m. The data were subjected to a conventional 3D processing sequence that included post-stack time migration. Tests with 3D pre-stack depth migration showed that such techniques can be applied to HR seismic surveys. Delineation of several horizons and fault surfaces reveals the potential for small-scale geologic and tectonic interpretation in three dimensions. Five major seismic facies and their detailed 3D geometries can be distinguished. Three fault surfaces and the top of a molasse surface were mapped in 3D. Analysis of the geometry of these surfaces and their relative orientation suggests that pre-existing structures within the Plateau Molasse (PM) unit influenced later faulting between the Plateau and SM. In particular, a change in strike of the PM bed dip may indicate a fold formed by a regional stress regime, the orientation of which was different from the one responsible for the creation of the Paudeze Fault Zone. This structure might have later influenced the local stress regime and caused the curved shape of the Paudeze Fault in our surveyed area.

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BACKGROUND: Since the late nineties, no study has assessed the trends in management and in-hospital outcome of acute myocardial infarction (AMI) in Switzerland. Our objective was to fill this gap. METHODS: Swiss hospital discharge database for years 1998 to 2008. AMI was defined as a primary discharge diagnosis code I21 according to the ICD10 classification. Invasive treatments and overall in-hospital mortality were assessed. RESULTS: Overall, 102,729 hospital discharges with a diagnosis of AMI were analyzed. The percentage of hospitalizations with a stay in an Intensive Care Unit decreased from 38.0% in 1998 to 36.2% in 2008 (p for trend < 0.001). Percutaneous revascularizations increased from 6.0% to 39.9% (p for trend < 0.001). Bare stents rose from 1.3% to 16.6% (p for trend < 0.001). Drug eluting stents appeared in 2004 and increased to 23.5% in 2008 (p for trend < 0.001). Coronary artery bypass graft increased from 1.0% to 3.0% (p for trend < 0.001). Circulatory assistance increased from 0.2% to 1.7% (p for trend < 0.001). Among patients managed in a single hospital (not transferred), seven-day and total in-hospital mortality decreased from 8.0% to 7.0% (p for trend < 0.01) and from 11.2% to 10.1%, respectively. These changes were no longer significant after multivariate adjustment for age, gender, region, revascularization procedures and transfer type. After multivariate adjustment, differing trends in revascularization procedures and in in-hospital mortality were found according to the geographical region considered. CONCLUSION: In Switzerland, a steep rise in hospital discharges and in revascularization procedures for AMI occurred between 1998 and 2008. The increase in revascularization procedures could explain the decrease in in-hospital mortality rates.

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Like numerous torrents in mountainous regions, the Illgraben creek (canton of Wallis, SW Switzerland) produces almost every year several debris flows. The total area of the active catchment is only 4.7 km², but large events ranging from 50'000 to 400'000 m³ are common (Zimmermann 2000). Consequently, the pathway of the main channel often changes suddenly. One single event can for instance fill the whole river bed and dig new several-meters-deep channels somewhere else (Bardou et al. 2003). The quantification of both, the rhythm and the magnitude of these changes, is very important to assess the variability of the bed's cross section and long profile. These parameters are indispensable for numerical modelling, as they should be considered as initial conditions. To monitor the channel evolution an Optech ILRIS 3D terrestrial laser scanner (LIDAR) was used. LIDAR permits to make a complete high precision 3D model of the channel and its surroundings by scanning it from different view points. The 3D data are treated and interpreted with the software Polyworks from Innovmetric Software Inc. Sequential 3D models allow for the determination of the variation in the bed's cross section and long profile. These data will afterwards be used to quantify the erosion and the deposition in the torrent reaches. To complete the chronological evolution of the landforms, precise digital terrain models, obtained by high resolution photogrammetry based on old aerial photographs, will be used. A 500 m long section of the Illgraben channel was scanned on 18th of August 2005 and on 7th of April 2006. These two data sets permit identifying the changes of the channel that occurred during the winter season. An upcoming scanning campaign in September 2006 will allow for the determination of the changes during this summer. Preliminary results show huge variations in the pathway of the Illgraben channel, as well as important vertical and lateral erosion of the river bed. Here we present the results of a river bank on the left (north-western) flank of the channel (Figure 1). For the August 2005 model the scans from 3 viewpoints were superposed, whereas the April 2006 3D image was obtained by combining 5 separate scans. The bank was eroded. The bank got eroded essentially on its left part (up to 6.3 m), where it is hit by the river and the debris flows (Figures 2 and 3). A debris cone has also formed (Figure 3), which suggests that a part of the bank erosion is due to shallow landslides. They probably occur when the river erosion creates an undercut slope. These geometrical data allow for the monitoring of the alluvial dynamics (i.e. aggradation and degradation) on different time scales and the influence of debris flows occurrence on these changes. Finally, the resistance against erosion of the bed's cross section and long profile will be analysed to assess the variability of these two key parameters. This information may then be used in debris flow simulation.

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This thesis has been conducted in the context of a lifestyle intervention in 40 Swiss kindergarten classes in the cantons St. Gallen and Vaud, in areas with a high migrant prevalence (Ballabeina study). The main objective of this work was to fill certain gaps of the literature and to bring a better understanding of the risk factors of overweight and obesity and their determinants in preschool children. Our data show that parental migrant status and educational level influence independently of each other adiposity and/or eating habits in these children. In addition, sports club participation at this young age seems to be a better indicator of healthy lifestyle characteristics in terms of physical activity, sedentary behaviour and eating habits than weight status. Finally, we found that in this population higher scores of hyperactivity/inattention are associated with lower adiposity and with both healthy (more physical activity and less sedentary activity) and unhealthy (more television viewing and more unhealthy eating habits) lifestyle characteristics. Thus, our findings can be used by different actors of health and education system to better target their preventive actions and can serve as a basis for future complementary researches. - Cette thèse a été réalisée dans le cadre d'un projet de promotion de la santé mené dans 40 classes enfantines suisses issues de régions à forte prévalence migrante des cantons de St. Gall et de Vaud (étude Ballabeina). L'objectif principal de ce travail était de combler certaines lacunes de la littérature et d'approfondir nos connaissances sur les facteurs de risque du surpoids et de l'obésité et de leurs déterminants chez les enfants d'âge préscolaire. Nos analyses montrent que le statut de migrant des parents et leur niveau d'éducation influencent indépendamment l'un de l'autres l'adiposité et les habitudes alimentaires chez ces enfants. De plus, à ce jeune âge la participation dans un club de sport semble être un meilleur indicateur de style de vie sain en termes d'activité physique, de comportements sédentaires et d'habitudes alimentaires que le statut pondéral. Nous avons également trouvé que dans cette population, un score plus élevé d'hyperactivité/inattention est associé aussi bien à des caractéristiques de style de vie saines (plus d'activité physique, moins d'activité sédentaire) que malsaines (plus de consommation de télévision et moins bonnes habitudes alimentaire. Ainsi, nos résultats peuvent aider les différents acteurs de la santé et de l'éducation à mieux cibler leurs actions de prévention et servir de base à de futures recherches complémentaires.

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OBJECTIVE: The sensitivity and tolerance regarding ADHD symptoms obviously differ from one culture to another and according to the informants (parents, teachers, or children). This stimulates the comparison of data across informants and countries. METHOD: Parents and teachers of more than 1,000 school-aged Swiss children (5 to 17 years old) fill in Conners's questionnaires on ADHD. Children who are older than 10 years old also fill in a self-report questionnaire. Results are compared to data from a North American sample. RESULTS: Swiss parents and teachers tend to report more ADHD symptoms than American parents and teachers as far as the oldest groups of children are concerned. Interactions are evidenced between school achievement, child gender, and informants. A relatively low rate of agreement between informants is found. CONCLUSION: These results strengthen the importance to take into account all informants in the pediatric and the child psychiatry clinic, as well as in the epidemiological studies.